1. Description of the Prior Art
According to a known method (see Norwegian Patent Application 916/69) the collar bones of a fish, of which the head has been severed by a circular cut, and which is advanced with its tail and leading, while its belly lobes slide along a pair of inclined surfaces, are severed from the body of the fish by a pair of rotating circular knives being spaced relative to each other and moving from the neck side transversely to the path of movement of the fish. This method is afflicted with the drawback that, due to the longitudinal advance of the fish the parts containing the collar bones are not cut-off with the accuracy as may be achieved when the head of the fish is severed by a wedge-shaped cut. The loss of valuable fish meat is considerable in this known method.
It is an object of this invention to provide a method and a device for cutting-off the head, the collar bones, the pectoral and the ventral fins from the body of a fish with a minimum loss of fish meat by gaining the parts containing the collar bones.
Another object of the invention is to provide a method and a device in which the parts containing the collar bones can be gained for separating from them the meat without manual handling
According to the invention the method includes the following steps:
A. aligning the head of each fish and securing it in position; PA1 B. severing said head by a wedge-shaped cut behind the collar bones; PA1 C. separating the parts containing the collar bones from the head by cuts extending into the gill cavity; PA1 D. removing said parts containing the collar bones and the head as well as the body of the fish to be processed further. PA1 a. aligning the part of the body of each fish behind its head in longitudinal direction along its plane of symmetry in an even level by resiliently engaging its vertebral column; PA1 b. aligning the head of the fish and securing it in position by straddling the gill cavity and supporting the head between the arc of the lower jaw; PA1 c. severing the head of the fish from the body by a wedge-shaped downwardly directed cut; PA1 d. separating the parts containing the collar bones from the head by downwardly directed cuts extending into the gill cavity; PA1 e. removing the parts containing the collar bones and the head as well as the body of the fish to be processed further.
Remarkable advantages are achieved in using the method according to the invention for fishes of which the gill and abdominal cavities have been opened wherein the head of each fish is fixed in position by straddling the gill cavity and supporting the head between the arc of the lower jaw, whereupon the body of the fish is cut-off and the parts containing the collar bones are separated from the head by cuts directed downwardly from the neck.
Advantageously the straddling support operation of each fish in its gill cavity is accompanied by aligning the fish in its transverse position and supporting it at the lower jaw in an even level, and wherein the body of the fish is centered with respect to its height and its lateral position by supporting the lower side of its vertebral column prior to the head severing operation.
A preferred method according to the invention for severing the heads of fishes after their gill and abdominal cavities have been opened and they have been gutted, comprises the following steps:
The device for carrying this preferred method into effect comprises an intermittently advanced endless conveyor including receiving means for the fishes and a head severing device with a pair of angularly arranged circular knives movable transversely relative to the path of movement of the fish, wherein the pair of circular knives are arranged with their nearly contacting cutting edges in the plane of symmetry of said receiving means and are mounted for pivoting motions about an axis extending in parallel relation to the path of movement of said conveyor, wherein a separating device comprises a pair of circular knives arranged in a common plane with their adjacent cutting edges defining a gap therebetween said separating device being mounted for pivoting motions through the path of movement of said receiving means and being arranged downstream of said beheading device spaced therefrom about the spacing between adjacent receiving means, and wherein further each receiving means comprises a support engaging the gill cavity supporting the fish and including a pair of supporting edges forming a top open "V" which include an angle of approximately 150.degree. and a head support adjacent said support, a vertically movable belly support lockable in its raised position and including a pair of wings arranged in V-shape and diverging with their outer edges in a roof gable-like manner downwardly, and a pivotal U-shaped top open trough.
This device may advantageously be provided with a substantially circular aperture at the apex of the pair of supporting edges of said support serving to receive the vertebral spine of the fish into which aperture a plurality of teeth project.
The outer edges of the belly support wings may advantageously be provided with downwardly directed saw teeth both wings carrying in unison a groove-like support surface.
The preferred embodiment of the device according to the invention comprises an intermittently advanced endless conveyor including receiving means for the fishes and a head severing device with a pair of angularly arranged circular knives movable transversely relative to the path of movement of the fish, wherein the pair of circular knives are arranged with their nearly contacting cutting edges in the plane of symmetry of said receiving means and are mounted for pivoting motions about an axis extending in parallel relation to the path of movement of said conveyor, wherein a separating device is provided comprising a pair of circular knives arranged in a common plane with their adjacent cutting edges defining a gap therebetween said separating device being mounted for pivoting motions through the path of movement of said receiving means and being arranged downstream of said beheading device spaced therefrom about the spacing between adjacent receiving means, and wherein further each receiving means comprises a support engaging the gill cavity supporting the fish and including a pair of supporting edges forming a top open "V" which include an angle of approximately 150.degree. and a head support adjacent said support, a vertically movable belly support lockable in its raised position and including a pair of wings arranged in V-shape and diverging with their outer edges in a roof gable-like manner downwardly, and a pivotal U-shaped top open trough, wherein a substantially circular aperture is provided at the apex of the pair of supporting edges of said support serving to receive the vertebral spine of the fish into which aperture a plurality of teeth project, wherein the outer edges of said belly support wings are provided with downwardly directed saw teeth both wings carrying in unison a groove-like support surface, and wherein said conveyor is advanced intermittently by drive means in a known per se manner said drive means simultaneously controlling the movements of said head severing device and said separating device during the stopping periods of said conveyor.
Without any limitation of its scope the invention shall now be described in detail in connection with the attached drawings showing schematically an exemplified preferred embodiment of the device with which the method according to the invention may be carried into effect.